This thesis examines the theory theory versus simulation theory debate, which
concerns how we reason about mental states. Theory theory (e.g .,
Carruthers, 1996a) argues that mental state reasoning is achieved using tacit
and non-tacit theories. Simulation theory argues that mental state reasoning is
achieved either by taking our own beliefs and desires offline, quarantining
them and using the beliefs and desires of the person we are reasoning about
(e.g., Goldman, 2006), or by imagining how we would respond in a situation
and assuming others are sufficiently like us such that they would respond in
the same manner (e.g., Heal, 1996). The thesis begins by demonstrating how
evidence from autism spectrum disorder fails to arbitrate decisively between
theory theory and simulation theory. Next, experimental work is reported using
counterfactual scenarios pertaining to mental states (plus a think aloud
requirement) in an attempt to arbitrate between theoretical positions.
Experiments 1 and 2 revealed more simulation and less theorising when we
reason about ourselves compared to reasoning about another person
Experiment 2 also demonstrated an effect of event controllability, with more
simulation and less theorising in controllable scenarios relative to
uncontrollable scenarios Experiment 3 indicated the presence of more
simulation but less theorising for familiar compared to unfamiliar scenarios.
Experiment 4 simultaneously manipulated the emotionality and familiarity of
scenarios and showed that increases in both emotionality and familiarity led to
more simulation, whereas unemotional and unfamiliar scenarios evoked more
theorising. Overall, the findings suggest the need for a hybrid model in which
recourse to theory-based or simulation-based reasoning is dependent on the
reasoner's perspective and the nature of scenario content.